Envelop.



G. F. A. MGDOUGALL.

ENVELOP.

APPLICATION FILED APR.22, 1014.

1,1 18,668, Patented Nov. 24, 1914.

WITNESSESI- INVENTEIFQ- y L Q. ATT u RNEY GEORGE E. A. MODOUGALL, OF BOSTON, MASSACHUSETTS.

ENVELOP.

Specification of Letters Patent.

Patented Nov. 24., iota;

Application filed April 22, 1914. Serial No. 833,820.

T all whom it may concern:

Be it known that I, GEORGE F. A. Mo- DOUGALL, a citizen of the United States, residing at Boston, in the county of Suffolk,

in the State of Massachusetts, have invented plain in detail hereinafter.

Briefly described my said improvement consists essentially, in providing overlapping sealed end portions for the end flaps; said overlapping portions being formed with curved lower edges that'conform to the curve of the safety flap as well as to the curve of the ordinary seal flap, and so that the safety devices are concealed and invisible when the envelop is held before a strong light.

In order to explain my said invention, I have provided the annexed drawings in which a 1 Figure 1 is an extended plan view of an envelop blank embodying my said improvements, and Fig. 2 is aback side view of the envelop as it appears when ready to receive a letter; the edge of the safety flap being crimped slightly to disclose the ordinary seal flap located behind said safety flap and coincident with the same so far as shape and size are concerned. Fig. 3 is an end view of said envelop showing particularly the safety and ordinary seal flaps as they appear before being closed down and sealed.

Referrin to these drawings, the letter (1 indicates the main or body portion of the envelop, b the ordinary seal flap and c-d the end flaps. End flap 0 is adapted to be folded down upon the body portion a and end flap (Z is gumined at cl, and is adapted to be folded down to overlap the end of flap 0 and to be sealed thereto, (see dotted lines Fig. 1 and full line Fig. 2 of the drawings.

The lower edges of the overlapping portions of the end flaps 0 and d are curved, as at m, to conform in size, curve and location to the correspondingly curved free edge portion 1 of the seal flap 6 as well as to the correspondingly curved free edge portion of the safety flap 6, so that when the envelop is completely sealed and ready to be mailed, the ordinary seal flap, the safety sealing flap and the overlapping sealed ends 'of the end flaps are outlined coincidently and so that, when the envelop is held up to a strong light and illuminated, the existence of the safety sealing flap and of the supplemental safety provided by the scaled overlapped portions of the end flaps cannot be detected.

The safety sealing flap e is, in effect, an extension to the back flap g; said back flap being adapted (in size and shape) to. be folded upon the body portion a, and the end flaps to be then folded thereupon in the usual manner. This brings the safety sealing flap 6 into coincidence with the ordinary seal flap b, as seen in Figs. 2 and 3. After a letter has been placed in the body of the envelop, the safety sealing flap e is moistened and tucked into the envelop and stuck to the inner side of the envelop, and the seal flap b is finally folded down and sealed.

If an attempt should be made to surreptitiously open or tamper with an envelop of my described, improved, construction, the first step would be to unseal (by steaming or otherwise) the seal flap proper b, when the sealed, overlapping, end flaps would be encountered and would have to be unsealed before one could openan end of the envelop, and gain access to the contents of the envelop, or it would be necessary to unscal and open the safety flap 6 before the interior of the envelop could be gained from the top, and it would be practically impossible to thus open an envelop, examine its contents, perhaps remove money or other valuables therefrom, and then reseal the envelop without leaving unmistakable evidence of such surreptitious opening.

Having thus described my invention, I claim as new and wish to secure by Letters Patent:

1. A safety envelop of the type referred to, including a safety lap, a seal flap proper, and overlapping sealed end flaps; all of said flaps being formed with edge portions that are coincident When the envelop is sealed.

2. In a safety envelop, in combination, a back flap having an extended safety flap adapted to be tucked and sealed to the inner face of the front sheet, end flaps having overlapped sealed end portions, and aseal 10 flap proper; said safety flap, seal flap and overlapped end flaps being formed with edges that are coincident When the envelop is sealed.

GEORGE F. A, MCDO'UGALL. Witnesses I FRANK H. ALLEN, AGNES BURKE.

Grantee e5 this patent may he obtained for five cents each, by addressing the Commissioner of Patents, Waahington, 10. G. 

